Mirror drum optical system for use in microscopic spectrophotometer

ABSTRACT

A mirror drum optical system for use in a microscopic spectrophotometer has a system of a lens and mirrors adapted to be inserted into and retracted from the optical path. A camera is arranged to photograph the specimen and the centering of the pinholes and reflex viewing system and photoindicator permit sequential observation and measurement by an observer.

IJite States atent Yonekubo [4 1 Feb. 27, 1973 MIRROR DRUM OPTICALSYSTEM FOR USE IN MICROSCOPIC SPECTROPIIOTOMETER Ken Yonekubo, Tokyo,Japan Olympus Optical Company Limited, Tokyo, Japan Feb. 7, 1972Inventor:

Assignee:

Filed:

Appl. No;

Foreign Application Priority Data Feb. 6, 1971 Japan ..46I450O US. Cl...356/96, 350/19, 356/73,

356/201, 356/219 Int. Cl .Q ..G0lj 3/42, GOln 21/06 Field of Search..356/74, 79, 83, 89, 96, 97, 356/201, 218, 219, 72, 73, 76; 350/12, 13,

Primary ExaminerRonald L. Wibert Assistant ExaminerV. P. McGrawAtt0rney-Eric H. Waters et al.

A mirror drum optical system for use in a microscopic spectrophotometerhasa system of a lens and mirrors adapted to be inserted into andretracted from the optical path. A camera is arranged to photograph thespecimen and the centering of the pinholes and reflex viewing system andphotoindicator permit sequential observation and measurement by anobserver.

ABSTRACT 1 Claim, 2 Drawing Figures Li Z 29 H 5726 H [l m L 1 a /{0 /2/3 0 ll M1 MIRROR DRUM OPTICAL SYSTEM FOR USE IN MICROSCOPICSPECTROPIIOTOMETER This invention relates to a mirror drum opticalsystem for use in a microscopic spectrophotometer.

Heretofore, it has been the common practice to use a microscopicspectrophotometer in case of measuring the spectrotransparency ofextremely small specimens. The prior technique applied to this kind ofapparatus makes use of a primary pinhole disposed on a specimen andadapted to produce a spot light by which is illuminated the portion ofthe specimen whose quality of light is to be measured and of a secondarypinhole disposed on the image plane given by an objective. The image ofthe primary pinhole is superposed upon the image of the secondarypinyole so as to effect centering of the two pinholes. This ensuresconsiderable decrease of flare of stray light from the outside therebyimproving the photometric accuracy. Thus, it is necessary to carry outcentering of the two pinholes. It is also necessary to use an auxiliaryillumination system which illuminates that portion of the specimen whichsurrounds the luminous spot illuminated by the photometric illuminationsystem. Thus, provision must be made of an optical system for use inobserving the centered condition of the two pinholes and of anotheroptical system for use in observing the specimen. Heretofore, it hasbeen the common practice to provide these two optical systems separatelyone from the other. Thus, the observer is obliged to change his attitudeat each time for observing the centering and specimen in sequence, andthis is troublesome in operation. Moreover, in case of using a livingcellular tissue as the specimen, which could not be colored, theauxiliary illumination system must be of one which can observe the phasecontrast of the specimen. However, the phase contrast microscopecomprising a condenser lens, a ring iris disposed on the condenser lens,an objective and a phase plate disposed on the objective operates tointerrupt the photometric luminous flux, thus rendering the photometricoperation impossible. In order to avoid such disadvantage use has beenmade of a common objective and a common condenser lens for thephotometric operation and these lenses have been replaced by a phasecontrast objective and a phase contrast condenser lens, respectively.Such interchange of the lenses causes change of the sight field owing tothe extremely small specimen even if the eccentricity of the lens systemis made as small as possible with the result that the photometricaccuracy becomes remarkably small. Even if the lens system has noeccentricity, the interchange of the objective and condenser lens ateach time of effecting the photometric operation and the observing andphotographing operations is very troublesome.

An object of the invention is to provide such a mirror drum opticalsystem for use in a microscopic spec- Other objects will appear in thefollowing specification, reference being had to the drawings, in which:

FIG. 1 is a diagrammatic illustration of an embodiment of a mirror drumoptical system for use in a microscopic spectrophotometer according tothe invention; and

FIG. 2 is a plan view illustrating a manner by which a primary pinholemay be aligned with a secondary pinhole by centering.

Referring to the drawings, reference numerals 1-8 designate aphotometric light source apparatus in which a luminous flux from aphotometric light source I passes through a collector lens 2 whichconverges the luminous flux on an entrance slit 3 of a spectroscope 4.The spectroscope 4 serves to disperse the luminous flux to monochromaticlights and converge them on an exit slit 5 which is then forms asecondary light source. The luminous flux from the exit slit 5 passesthrough a slit projecting lens 6 and arrives at a primary pinhole 7where the luminous flux is squeezed. The luminous flux is then reflectedby a reflecting mirror 8 and passes through a semi-transparent prism 9and then is converged on a focus located in front of a condenser lens14. The semi-transparent prism 9 is adapted to be inserted into andretracted from the optical path. The image of the primary pinhole 7 isgiven on a specimen 15 by the instrumentality of the condenser lens 14and this image is used as a spot illumination.

Reference numerals 10-13 designate a light source apparatus for use indetecting the phase contrast. The luminous flux from an auxiliary lightsource 10 passes through a collector lens 11 by which is converged theluminous flux on a ring iris 12. The luminous flux passed through thering iris I2 falls on a relay lens 13 and then is reflected by thesemi-transparent prism 9 onto a focus located in front of the condenserlens 14.

The luminous flux passed through the specimen 15 falls on an objective16 and a phase plate projecting lens 17. The image formed at the focuslocated behind the objective lens 16 is reflected by a first reflectingmirror 18 and then given on a phase plate 19. The ring iris 12 and thephase plate 19 are conjugate each other. The image of the specimen 15 isgiven between the phase plate projecting lens 17 and the phase plate 19and this image passes through a second relay lens 20 and an eyepiece 23to the eye 24. If the photometric light source 1 and the auxiliary lightsource 10 are simultaneously energized, the eye 4 can observe the imageof the specimen 15 and the image of the first pinhole 7 superposed oneupon the other. Thus, during this observation of the specimen 15 thedisplacement of the stage, for instance, permits of obtaining on thedesired position of the specimen 15 the image of the first pinhole 7.

Between the relay lens 20 and the eyepiece 23 is arranged a fourthreflecting mirror 21 adapted to be inserted into and retracted from theoptical path to form the image of the specimen 15 through an eyepiece 30on a photosensitive film 31 thereby taking a photograph of the specimen15. (F

If the phase plate projecting lens 17 and the reflecting mirror 18 areretracted from the optical path, the spot image on the specimen 15, thatis, the image of the primary pinhole 7 is formed on a secondary pinhole25 by means of the objective 16. The luminous flux from the secondarypinhole 25 is impinged through a first relay lens 26, second reflectingmirror 27, third relay lens 28, third reflecting mirror 29, fifthreflecting mirror 22, and eyepiece 23 on the eye 24. Under suchcondition the eye 24 can sight the images of the primary pinhole 7 andof the secondary pinhole 25 superposed one upon the other and also sightthe minute portion of the specimen as shown in FIG. 2. The objective 16is made adjustable in a direction perpendicular to the optical axis toperform the centering until the image of the primary pinhole 7 iscoincident with the image of the secondary pinhole 25.

If the second reflecting mirror 27 is retracted from the optical path,the luminous flux from the relay lens 26 falls on a light receiver 32 towhich is electrically connected an indicator 33 which makes it possibleto measure the quantity of light impinged on the specimen 15.

In the above mentioned four operations according to the invention, useis made of the following optical elements. That is,

l. in case of observing the specimen 15, use is made of the opticalelements 16, 17, 18, 19, 20, 23 and 24,

2. in case of observing the centered condition of the pinholes 7 and 25,use is made of the optical elements 16, 25, 26, 27, 28, 29,22, 23 and24,

3. in case of measuring the quantity of light impinged on the specimen15, use is made of the optical elements 16, 25, 26, 32 and 33, and

4. in case of taking photograph, use is made of the optical elements 16,17, 18, 19,20, 21, 30 and 31.

The relay lens 26 serves to project the rear focus of the objective 16upon the light receiving surface of the light receiver 32 with theresult that there is no risk of the light receiver 32 being struggled bythe configuration of the specimen 15. In the lens system present in theoptical path between the objective 16 and the light receiver 32 duringthe photometric operation, the relay lens 26 only absorbs light so thatthere is substantially no loss in the quantity of light therebyimproving the photometric accuracy.

During the specimen observing and photographing operations the presenceof the reflecting mirror 18 or 27 prevents the light receiver 32 frombeing impinged by the light with the result that the life of the lightreceiver 32 becomes long.

In the microscopic spectrophotometric successive operations with the aidof the apparatus according to the invention, in the first place theauxiliary light source 10 is energized and then the semi-transparentprism 9, lens 17 and reflecting mirror 18 are inserted into the opticalpath to observe the phase contrast of the specimen 15. If it is desiredto take photograph, the reflecting mirror 21 may be inserted into theoptical path.

Secondly, the photometric light source 1 is energized and the primarypinhole 7 is adjusted until the primary pinhole 7 is coincident with theouter periphery of the minute portion of the specimen 15, therebyobtaining a spot illumination. The semi-transparent prism 9, lens 17 andreflecting mirror 18 are retracted from the optical path and thereflecting mirrors 27, 29 and 22 are inserted into the optical path toform the image of the primary pinhole 7 on the secondary pinhole 25 bymeans of the objective 16. Then, the objective 16 is adjusted to effectthe centering of the pinholes.

The reflecting mirror 27 is retracted from the optical path after thecorrect centering of the pinholes has been performed to measure thequantity of light impinged on the specimen 15.

If it is desired to take photograph under the correct centered conditionof the pinholes, the lens 17 and reflecting mirrors 18 and 21 areinserted into the optical path and the reflecting mirror 29 is retractedfrom the optical path. In this case the photographed portionsubstantially corresponds to that portion of the specimen 15 whosequantity of light has been measured.

As explained hereinbefore, the use of the optical system, that is, thereflecting mirrors 18, 21, 22, 27, 29, semi-transparent prism 9 andeventually lens 17 adapted to be inserted into and retracted from theoptical path in accordance with the invention ensures interchange of thefour operations of observing the specimen, centering the pinholes,measuring the quantity of light and of taking photograph in a positiveand simple manner and further provides the important ad vantage thattroublesome and time consuming interchange between the objective and thecondenser lens can be avoided, and that microscopic spectrophotometercan reliably be operated, thereby improving the photometric accuracy,

In the above mentioned example use is made of the reflecting mirror 29adapted to be inserted into and retracted from the optical path. Thereflecting mirror 29 may be replaced by a stationary semi-transparentmirror since the reflecting mirror 29 is excluded out of the photometricoptical axis. Moreover, instead of the two reflecting mirrors 21 and 22use may be made of one reflecting mirror adapted to be rotated by independence with the centering or photographing operation. However, it ispreferable to use the two selectively displaceable reflecting mirrors 21and 22 rather than one rotatable reflecting mirror which causes theclick stop mechanism to decrease its accura- What is claimed is:

1. A mirror drum optical system for use in a microscopicspetrophotometer comprising a photometric light source apparatusincluding a primary pinhole, a light source apparatus including a ringiris and illuminating the phase contrast, a specimen, a semi-transparentprism adapted to illuminate said specimen located on the same opticalaxis from said two light source apparatus, an objective and lightreceiver located on said optical axis, a first reflecting mirror adaptedto be inserted into and retracted from said optical axis, a secondarypinhole, a first relay lens and a second reflecting mirror adapted to beinserted into and retracted from said optical axis, said mirrors andlens being arranged on said optical axis between said objective andlight receiver, a phase plate, a second relay lens and eyepiece arrangedin sequence on the optical axis bent by said first reflecting mirror, aphase plate projecting lens arranged between said objective and saidphase plate, a third relay lens located on the optical axis bent by saidsecond reflecting mirror, a third reflecting mirror adapted to beinserted into and retracted from the optical path or a stationarysemitransparent mirror for bending said optical axis including saidthird relay lens towards a direction extending in parallel with saidoptical axis from said objective to third reflecting mirror, a fifthreflecting mirror located at said crossed position and adapted to beinserted into and retracted from the optical path and to bend saidoptical axis bent by said third reflecting mirror or semitransparentmirror towards said eyepiece, and a photographic eyepiece located onsaid optical axis bent by said fourth reflecting mirror and leading to aphotographic film.

1. A mirror drum optical system for use in a microscopicspetrophotometer comprising a photometric light source apparatusincluding a primary pinhole, a light source apparatus including a ringiris and illuminating the phase contrast, a specimen, a semi-transparentprism adapted to illuminate said specimen located on the same opticalaxis from said two light source apparatus, an objective and lightreceiver located on said optical axis, a first reflecting mirror adaptedto be inserted into and retracted from said optical axis, a secondarypinhole, a first relay lens and a second reflecting mirror adapted to beinserted into and retracted from said optical axis, said mirrors andlens being arranged on said optical axis between said objective andlight receiver, a phase plate, a second relay lens and eyepiece arrangedin sequence on the optical axis bent by said first reflecting mirror, aphase plate projecting lens arranged between said objective and saidphase plate, a third relay lens located on the optical axis bent by saidsecond reflecting mirror, a third reflecting mirror adapted to beinserted into and retracted from the optical path or a stationarysemi-transparent mirror for bending said optical axis including saidthird relay lens towards a direction extending in parallel with saidoptical axis from said objective to said light receiver andperpendicular to said optical axis bent by said first reflecting mirror,said optical axis bent by said third reflecting mirror orsemi-transparent mirror being perpendicular to and crossed with saidoptical axis bent by said first reflecting mirror at the intermediatebetween said second relay lens and said eyepiece, a fourth reflectingmirror located at said crossed position and adapted to be inserted intoand retracted from the optical path and to bend said optical axis bentby said first reflecting mirror towards said third reflecting mirror, afifth reflecting mirror located at said crossed position and adapted tobe inserted into and retracted from the optical path and to bend saidoptical axis bent by said third reflecting mirror or semi-transparentmirror towards said eyepiece, and a photographic eyepiece located onsaid optical axis bent by said fourth reflecting mirror and leading to aphotographic film.